4.12.9 Running Commands on the Master

Occasionally, it is useful to execute some task on the master, for example to
create a directory, deploy a build result, or trigger some other centralized
processing. This is possible, in a limited fashion, with the
MasterShellCommand step.

This step operates similarly to a regular ShellCommand, but executes on
the master, instead of the slave. To be clear, the enclosing Build
object must still have a slave object, just as for any other step – only, in
this step, the slave does not do anything.

In this example, the step renames a tarball based on the day of the week.